Thermostatic circuit closer



Nov. 8, 1927.

H. M. BALDWIN- ET AL TI-IERIJOS'IA'IIC CIRCUIT CLOSER Filed Sept. 30.. 1922 v gnucnhyq) Hub aI'TM- Baldwin H2111" M Tranur W W Quentin f.

Patented Nov. 8, 1927.

UNITED STATES PATENT OFFICE.

HOBART M. BALDWIN AND HENRY M. TRENOR, F GARY, WEST VIRGINIA.

THERMOSTATIC CIRCUIT CLOSER.

Application filed September 30, 1922.

This invention relates to a circuit closer which may be used as a temperature alarm, and the primary object of the invention is to provide a simple and durable device for giving a suitable signal when the temperature reaches or exceeds a predetermined degree.

Another object of the invention is to provide a circuit closer embodying a thermometer, the expansible medium of which is adapted to close a circuit through a suitable signal or alarm when the temperature reaches a predetermined degree, the device being so arranged as to permit the use thereof for various purposes, such as fire alarms,

and the like.

A further object of the invention is the provision of a circuit closer embodying a thermometer having a stationary electrode arranged thereinadjacent to one end thereof, and an adjustable electrode arranged therein at the other end thereof, the adjustable electrode permitting the signal to be sounded at any given temperature.

A further object of the invention is to provide a novel means for associating the adjustable electrode; with the thermometer, whereby a vacuum can be maintained in the thermometer.

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of part s, as will be hereinafter more specifically described, claimed and illustrated in the accompanying drawings. forming a part of this specification in which drawings:

Figure 1 is a vertical longitudinal section through the improved temperature alarm or signal.

Figure 2 is a front elevation of the same, showing the circuit therefor diagrammatically.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the reference character A generally indicates the improved temperature alarm, which includes a thermometer tube 5, which can be secured in any preferred manner, such as by metal straps 6 to a base plate 7. This base plate 7 is preferably made of non-conducting material, such as hard wood and has its outer face grooved for the reception of the thermometer tube 5. 55 This tube 5 can be graduated as at 8 or the face of the base plate itself can be grad- Serial No. 591,535.

uated. The lower end of the thermometer tube 5 is provided with the usual bulb 9 as can be clearly seen by referring to Figures 1 and 2 of the drawings. The upper end of the tube 5 is preferably left open and provided with the novel means D for sealing the upper end thereof. The tube 5 and the bulb 6 preferably contains a quantity of mercury 10, which is used for the dual purpose of indicating change in temperature and for also closing and opening a circuit, as will be hereinafter more fully described. The bulb 9 has inserted therein a suitable wire or metal strip 11, which is adapted to be normally engaged by the mercury 10 in the tube and bulb. This wire or conducting strip 11 can be incorporated with the thermometer tube 5 at the time of manufacture thereof.

The upper end of the thermometer tube 5 is provided with relatively fine external threads 12 for receiving the novel sealin means B which will be now described.

The novel sealing means B comprises a cap 13 having a bore extending entirely through the same. The inner end of the bore is enlarged in diameter and provided with screw threads 14 for receiving the upper end of the thermometer 5. The enlarged portion 14 of the bore also defines a shoulder 15 and a suitable washer 16 is placed upon the upper end ofthe thermometer tube, and is adapted to be engaged by said shoulder. This washer may be made of any preferred material, such as felt or the like, and is provided with a relatively small axial bore, the purpose of which will be hereinafter more fully described. The outer or smaller end of the bore of the cap 13 is also provided with screw threads 17, and this portion of the bore is adapted to receive an externally threaded hollow stem 18 having a cup shaped head 19 formed thereon to facilitate the turning of the stem 18 into and out of the cap. The stem is provided with a bore 20 through which the second conducting wire or strip 21 is inserted. This strip or wire 21 also extends through the washer 16 and can be initially positioned any desired distance within the thermometer tube 5. If so desired, this wire or conducting strip 21 can be rigidly secured within the bore 20 of the stem 18 in any preferred way.

If so desired, the head 19 can carry a suitable stufiing box 22, in order to absolutely seal the upper end of the thermometer tube and to prevent the entrance of air around the said conducting strip or wire 21. As shown, the head 19 of the stem 18 is hollowed out, as at 23 for the reception of a suitable packing 24 and the hollowed por tion of the head can be provided with threads for the reception of the plug 25, which is utilized for compressing the packing 24 and for forcing the same into intimate contact with the wire or conducting strip 21. The plug 25, is of course, provided with an axial bore for the reception of the conducting strip or wire 21. This packing 24 may be of any desired i'naterial and the same performs the dual function of sealing the upper end of the stem and forn'ung a grip for engaging the wire 21, so that when the stem'18 is rotated, the wire will be turned therewith. Thus, if so desired, this packing 24 may be in the nature of some cementitious material so as to firmly b nd the wire in position.

The upper and lower terminals of the base plate 7 are provided with suitable binding posts 27 and 28, to which are detachably secured by means of suitable binding nuts 29 and 30, the terminals of the conducting strips or wires 11 and 21. These binding posts 27 and 28 also serve as means for holding the line or feed wires 31 and 32 in position. The wires 31 and 32 may be connected to any suitable type of signal or alarm either of the audible or visible variety, and as shown, an ordinary electric bell is used. A suitable battery 31 of any character, can be interposed in either the wire 32 or 31 for supplying the necessary energy for actuating the bell 33 or other signal.

By turning the stem 18, the wire or conducting strip 21 can be placed at various distances within the thermometer tube 5, and thus this coin'liarting strip or wire 21 can be set at any desired temperature within certain limits. During the adjustment of the stem 18, the upper end of the wire 21 can be removed from the binding post 27 and placed around the same after the wire has been moved to its adjusted position.

Now, say it is desired, that an alarm be given when the temperature arises above 85, the stem 18 is rotated, until the lower end of the wire reaches this degree of temperature indicated by the scale on the thermometer tube. Now, it is obvious that when the temperature arises to or above this degree, the mercury will engage the wire or conductor strip 21, thus bridging the gap between the contacts or wires 11 and 21 and closing the circuit through the signal indicated by the bell 33. It is obvious that the improved temperature alarm can be used for various purposes, such as for controlling furnaces and the like giving signals in case of fire. If so desired, one of the thermom etcrs or temperature alarms can be placed in each room of a building or other desired spaced points and a signal provided for each alarm and placed at a central switch board, so that all of the signals could be viewed simultaneously. Movement of the stem 18 will permit an adjustment of about to be given to the wire or conducting strip 21, and it can be seen that a longer wire can be substituted for the wire 21 when so desired, or the wire 21 forced manually further into the hub or out of the tube 5 through the stem 18, by loosening the plug of the stufling box 22.

Changes in details may be made without departing from the spirit or scope of this invention; but,

\Ve claim:

In a circuit closer, a base plate, a thermometer tube secured to said base late and open at its upper end, a cap on the upper end portion of said thermometer tube and having a longitudinally extending threaded passage aligned with the tube, a hollow stein screwed into the threaded passage of said cap for adjustment longitudinally of the cap, said stem having its upper end portion provided with a cup shaped head internally threaded. a conductor extending into said thermometer tube at the lower end portion thereof, a second conductor passing thru said cap shaped head and stem, and extending into the upper end portion of said" thermometer tube, a packing in the cup shaped head of said stem, and a hollow plug screwed into the cup shaped head of said stem and having engagement with the packing to compress the same, the second conductor being projected thru said packing and plug beyond the upper end thereof.

HOBART M. BALDVIN.

HENRY MI TRENOR. 

